SAS apps not loading on CentOS

Wonderland seems to work pretty well on CentOS, **except** the famous SAS issue ..: shared apps do not start and we get messages like: "X Window Manager creation failed:
[java] java.lang.Error: Failed to create socket: java.io.IOException: Cannot connect to X server"

There's already a few posts around this issue. Solutions indicated are not straightforward to understand -- could anyone who solved this problem write a few lines telling exactly the process to solve the problem ?